Carbochlorination of dispersed oxides in a molten salt reactor

Abstract

Reaction mechanism and rates were determined from 803 to 1,073 K for the carbochlorination of AI,O, and of Al, Si and Fe-mixed oxides using CI, and C slurried in a stirred melt of NaCI-AICI,. Alumina chlorination rates of 0.33-2.0 x kmol/s were obtained using C:melt weight ratios between 1:21 and 1:42. The reaction rate was proportional to C loading at temperatures below 923 K, while gas-liquid mass transfer was rate-controlling at higher temperatures. Carbochlorination of the combined oxides in coal fly ash at 923 K and oxide conversions less than about 50% was also gas-liquid mass-transfer-controlled. At higher conversions, dissolution became the rate-controlling factor. A 40% (molar) AICI, melt was more effective than a 48% AICI, melt for the selective chlorination of AI,O, over SiO,.